The invention discloses a multi-electrode rotary spark gap switch used for a high-voltage pulse powder supply, and belongs to the technical field of pulse power. The switch comprises a stator (8), a rotor (7), a rotor needle electrode (9), a stator needle electrode (10) and a drive motor (1). The stator (8) and the rotor (7) are respectively provided with 2N layers of the needle electrodes, each layer of the stator (8) is provided with M stator needle electrodes (10), the stator needle electrodes are connected with a lead to keep the same electric potential, one rotor needle electrode (9) is arranged at each layer of the rotor (7), the rotor needle electrodes of two adjacent layers keep a 180-degree mechanical angle, and are directly connected with a lead to keep the same electric potential, and the switch is turned on when the motor drives the rotor to rotate until the rotor needle electrode and the stator needle electrode are opposite. The switch has the advantages of high switching voltage, high switching power and high frequency of repetitive work, fast switching speed less than 10ns, simple insulation structure, long service life, convenient maintenance, low cost, etc.